/* * Copyright (C) 2010 NXP Semiconductors * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * You should have received a copy of the GNU General Public License along * with this program; if not, write to the Free Software Foundation, Inc., * 675 Mass Ave, Cambridge, MA 02139, USA. */ #include <linux/kernel.h> #include <linux/module.h> #include <linux/init.h> #include <linux/platform_device.h> #include <linux/spinlock.h> #include <linux/rtc.h> #include <linux/slab.h> #include <linux/io.h> #include <linux/of.h> /* * Clock and Power control register offsets */ #define LPC32XX_RTC_UCOUNT 0x00 #define LPC32XX_RTC_DCOUNT 0x04 #define LPC32XX_RTC_MATCH0 0x08 #define LPC32XX_RTC_MATCH1 0x0C #define LPC32XX_RTC_CTRL 0x10 #define LPC32XX_RTC_INTSTAT 0x14 #define LPC32XX_RTC_KEY 0x18 #define LPC32XX_RTC_SRAM 0x80 #define LPC32XX_RTC_CTRL_MATCH0 (1 << 0) #define LPC32XX_RTC_CTRL_MATCH1 (1 << 1) #define LPC32XX_RTC_CTRL_ONSW_MATCH0 (1 << 2) #define LPC32XX_RTC_CTRL_ONSW_MATCH1 (1 << 3) #define LPC32XX_RTC_CTRL_SW_RESET (1 << 4) #define LPC32XX_RTC_CTRL_CNTR_DIS (1 << 6) #define LPC32XX_RTC_CTRL_ONSW_FORCE_HI (1 << 7) #define LPC32XX_RTC_INTSTAT_MATCH0 (1 << 0) #define LPC32XX_RTC_INTSTAT_MATCH1 (1 << 1) #define LPC32XX_RTC_INTSTAT_ONSW (1 << 2) #define LPC32XX_RTC_KEY_ONSW_LOADVAL 0xB5C13F27 #define RTC_NAME "rtc-lpc32xx" #define rtc_readl(dev, reg) \ __raw_readl((dev)->rtc_base + (reg)) #define rtc_writel(dev, reg, val) \ __raw_writel((val), (dev)->rtc_base + (reg)) struct lpc32xx_rtc { void __iomem *rtc_base; int irq; unsigned char alarm_enabled; struct rtc_device *rtc; spinlock_t lock; }; static int lpc32xx_rtc_read_time(struct device *dev, struct rtc_time *time) { unsigned long elapsed_sec; struct lpc32xx_rtc *rtc = dev_get_drvdata(dev); elapsed_sec = rtc_readl(rtc, LPC32XX_RTC_UCOUNT); rtc_time_to_tm(elapsed_sec, time); return rtc_valid_tm(time); } static int lpc32xx_rtc_set_mmss(struct device *dev, unsigned long secs) { struct lpc32xx_rtc *rtc = dev_get_drvdata(dev); u32 tmp; spin_lock_irq(&rtc->lock); /* RTC must be disabled during count update */ tmp = rtc_readl(rtc, LPC32XX_RTC_CTRL); rtc_writel(rtc, LPC32XX_RTC_CTRL, tmp | LPC32XX_RTC_CTRL_CNTR_DIS); rtc_writel(rtc, LPC32XX_RTC_UCOUNT, secs); rtc_writel(rtc, LPC32XX_RTC_DCOUNT, 0xFFFFFFFF - secs); rtc_writel(rtc, LPC32XX_RTC_CTRL, tmp &= ~LPC32XX_RTC_CTRL_CNTR_DIS); spin_unlock_irq(&rtc->lock); return 0; } static int lpc32xx_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *wkalrm) { struct lpc32xx_rtc *rtc = dev_get_drvdata(dev); rtc_time_to_tm(rtc_readl(rtc, LPC32XX_RTC_MATCH0), &wkalrm->time); wkalrm->enabled = rtc->alarm_enabled; wkalrm->pending = !!(rtc_readl(rtc, LPC32XX_RTC_INTSTAT) & LPC32XX_RTC_INTSTAT_MATCH0); return rtc_valid_tm(&wkalrm->time); } static int lpc32xx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *wkalrm) { struct lpc32xx_rtc *rtc = dev_get_drvdata(dev); unsigned long alarmsecs; u32 tmp; int ret; ret = rtc_tm_to_time(&wkalrm->time, &alarmsecs); if (ret < 0) { dev_warn(dev, "Failed to convert time: %d\n", ret); return ret; } spin_lock_irq(&rtc->lock); /* Disable alarm during update */ tmp = rtc_readl(rtc, LPC32XX_RTC_CTRL); rtc_writel(rtc, LPC32XX_RTC_CTRL, tmp & ~LPC32XX_RTC_CTRL_MATCH0); rtc_writel(rtc, LPC32XX_RTC_MATCH0, alarmsecs); rtc->alarm_enabled = wkalrm->enabled; if (wkalrm->enabled) { rtc_writel(rtc, LPC32XX_RTC_INTSTAT, LPC32XX_RTC_INTSTAT_MATCH0); rtc_writel(rtc, LPC32XX_RTC_CTRL, tmp | LPC32XX_RTC_CTRL_MATCH0); } spin_unlock_irq(&rtc->lock); return 0; } static int lpc32xx_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled) { struct lpc32xx_rtc *rtc = dev_get_drvdata(dev); u32 tmp; spin_lock_irq(&rtc->lock); tmp = rtc_readl(rtc, LPC32XX_RTC_CTRL); if (enabled) { rtc->alarm_enabled = 1; tmp |= LPC32XX_RTC_CTRL_MATCH0; } else { rtc->alarm_enabled = 0; tmp &= ~LPC32XX_RTC_CTRL_MATCH0; } rtc_writel(rtc, LPC32XX_RTC_CTRL, tmp); spin_unlock_irq(&rtc->lock); return 0; } static irqreturn_t lpc32xx_rtc_alarm_interrupt(int irq, void *dev) { struct lpc32xx_rtc *rtc = dev; spin_lock(&rtc->lock); /* Disable alarm interrupt */ rtc_writel(rtc, LPC32XX_RTC_CTRL, rtc_readl(rtc, LPC32XX_RTC_CTRL) & ~LPC32XX_RTC_CTRL_MATCH0); rtc->alarm_enabled = 0; /* * Write a large value to the match value so the RTC won't * keep firing the match status */ rtc_writel(rtc, LPC32XX_RTC_MATCH0, 0xFFFFFFFF); rtc_writel(rtc, LPC32XX_RTC_INTSTAT, LPC32XX_RTC_INTSTAT_MATCH0); spin_unlock(&rtc->lock); rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_AF); return IRQ_HANDLED; } static const struct rtc_class_ops lpc32xx_rtc_ops = { .read_time = lpc32xx_rtc_read_time, .set_mmss = lpc32xx_rtc_set_mmss, .read_alarm = lpc32xx_rtc_read_alarm, .set_alarm = lpc32xx_rtc_set_alarm, .alarm_irq_enable = lpc32xx_rtc_alarm_irq_enable, }; static int lpc32xx_rtc_probe(struct platform_device *pdev) { struct resource *res; struct lpc32xx_rtc *rtc; int rtcirq; u32 tmp; rtcirq = platform_get_irq(pdev, 0); if (rtcirq < 0 || rtcirq >= NR_IRQS) { dev_warn(&pdev->dev, "Can't get interrupt resource\n"); rtcirq = -1; } rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL); if (unlikely(!rtc)) { dev_err(&pdev->dev, "Can't allocate memory\n"); return -ENOMEM; } rtc->irq = rtcirq; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); rtc->rtc_base = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR(rtc->rtc_base)) return PTR_ERR(rtc->rtc_base); spin_lock_init(&rtc->lock); /* * The RTC is on a separate power domain and can keep it's state * across a chip power cycle. If the RTC has never been previously * setup, then set it up now for the first time. */ tmp = rtc_readl(rtc, LPC32XX_RTC_CTRL); if (rtc_readl(rtc, LPC32XX_RTC_KEY) != LPC32XX_RTC_KEY_ONSW_LOADVAL) { tmp &= ~(LPC32XX_RTC_CTRL_SW_RESET | LPC32XX_RTC_CTRL_CNTR_DIS | LPC32XX_RTC_CTRL_MATCH0 | LPC32XX_RTC_CTRL_MATCH1 | LPC32XX_RTC_CTRL_ONSW_MATCH0 | LPC32XX_RTC_CTRL_ONSW_MATCH1 | LPC32XX_RTC_CTRL_ONSW_FORCE_HI); rtc_writel(rtc, LPC32XX_RTC_CTRL, tmp); /* Clear latched interrupt states */ rtc_writel(rtc, LPC32XX_RTC_MATCH0, 0xFFFFFFFF); rtc_writel(rtc, LPC32XX_RTC_INTSTAT, LPC32XX_RTC_INTSTAT_MATCH0 | LPC32XX_RTC_INTSTAT_MATCH1 | LPC32XX_RTC_INTSTAT_ONSW); /* Write key value to RTC so it won't reload on reset */ rtc_writel(rtc, LPC32XX_RTC_KEY, LPC32XX_RTC_KEY_ONSW_LOADVAL); } else { rtc_writel(rtc, LPC32XX_RTC_CTRL, tmp & ~LPC32XX_RTC_CTRL_MATCH0); } platform_set_drvdata(pdev, rtc); rtc->rtc = devm_rtc_device_register(&pdev->dev, RTC_NAME, &lpc32xx_rtc_ops, THIS_MODULE); if (IS_ERR(rtc->rtc)) { dev_err(&pdev->dev, "Can't get RTC\n"); return PTR_ERR(rtc->rtc); } /* * IRQ is enabled after device registration in case alarm IRQ * is pending upon suspend exit. */ if (rtc->irq >= 0) { if (devm_request_irq(&pdev->dev, rtc->irq, lpc32xx_rtc_alarm_interrupt, 0, pdev->name, rtc) < 0) { dev_warn(&pdev->dev, "Can't request interrupt.\n"); rtc->irq = -1; } else { device_init_wakeup(&pdev->dev, 1); } } return 0; } static int lpc32xx_rtc_remove(struct platform_device *pdev) { struct lpc32xx_rtc *rtc = platform_get_drvdata(pdev); if (rtc->irq >= 0) device_init_wakeup(&pdev->dev, 0); return 0; } #ifdef CONFIG_PM static int lpc32xx_rtc_suspend(struct device *dev) { struct platform_device *pdev = to_platform_device(dev); struct lpc32xx_rtc *rtc = platform_get_drvdata(pdev); if (rtc->irq >= 0) { if (device_may_wakeup(&pdev->dev)) enable_irq_wake(rtc->irq); else disable_irq_wake(rtc->irq); } return 0; } static int lpc32xx_rtc_resume(struct device *dev) { struct platform_device *pdev = to_platform_device(dev); struct lpc32xx_rtc *rtc = platform_get_drvdata(pdev); if (rtc->irq >= 0 && device_may_wakeup(&pdev->dev)) disable_irq_wake(rtc->irq); return 0; } /* Unconditionally disable the alarm */ static int lpc32xx_rtc_freeze(struct device *dev) { struct platform_device *pdev = to_platform_device(dev); struct lpc32xx_rtc *rtc = platform_get_drvdata(pdev); spin_lock_irq(&rtc->lock); rtc_writel(rtc, LPC32XX_RTC_CTRL, rtc_readl(rtc, LPC32XX_RTC_CTRL) & ~LPC32XX_RTC_CTRL_MATCH0); spin_unlock_irq(&rtc->lock); return 0; } static int lpc32xx_rtc_thaw(struct device *dev) { struct platform_device *pdev = to_platform_device(dev); struct lpc32xx_rtc *rtc = platform_get_drvdata(pdev); if (rtc->alarm_enabled) { spin_lock_irq(&rtc->lock); rtc_writel(rtc, LPC32XX_RTC_CTRL, rtc_readl(rtc, LPC32XX_RTC_CTRL) | LPC32XX_RTC_CTRL_MATCH0); spin_unlock_irq(&rtc->lock); } return 0; } static const struct dev_pm_ops lpc32xx_rtc_pm_ops = { .suspend = lpc32xx_rtc_suspend, .resume = lpc32xx_rtc_resume, .freeze = lpc32xx_rtc_freeze, .thaw = lpc32xx_rtc_thaw, .restore = lpc32xx_rtc_resume }; #define LPC32XX_RTC_PM_OPS (&lpc32xx_rtc_pm_ops) #else #define LPC32XX_RTC_PM_OPS NULL #endif #ifdef CONFIG_OF static const struct of_device_id lpc32xx_rtc_match[] = { { .compatible = "nxp,lpc3220-rtc" }, { } }; MODULE_DEVICE_TABLE(of, lpc32xx_rtc_match); #endif static struct platform_driver lpc32xx_rtc_driver = { .probe = lpc32xx_rtc_probe, .remove = lpc32xx_rtc_remove, .driver = { .name = RTC_NAME, .owner = THIS_MODULE, .pm = LPC32XX_RTC_PM_OPS, .of_match_table = of_match_ptr(lpc32xx_rtc_match), }, }; module_platform_driver(lpc32xx_rtc_driver); MODULE_AUTHOR("Kevin Wells <wellsk40@gmail.com"); MODULE_DESCRIPTION("RTC driver for the LPC32xx SoC"); MODULE_LICENSE("GPL"); MODULE_ALIAS("platform:rtc-lpc32xx");